The utility model provides an all opened the pre -installation groove on the stabilizer blade, the pre -installation inslot is provided with elastomeric element that a W type fitting pin for insulator chain, including the shank, the shank is connected gradually and is become certain contained angle by four stabilizer blades to be formed, and four stabilizer blades are first outer stabilizer blade, first interior stabilizer blade, the interior stabilizer blade of second, the outer stabilizer blade of second in proper order, and the shank is formed by integrative curved system of flat steel, the shank. The utility model provides a have ultra -long life, can effectively avoid W type fitting pin by the novel W type fitting pin of flattened.